The Neurodevelopmental Dynamics of Multilingual Experience During Childhood: A Longitudinal Behavioral, Structural, and Functional MRI Study.

Abstract

Background/objectives: A neurobiological framework of bi- or multilingual neurocognitive development must consider the following: (i) longitudinal behavioral and neural measures; (ii) brain developmental constraints across structure and function; and (iii) the development of global multilingual competence in a homogeneous social environment. In this study, we investigated whether multilingual competence yields early changes in executive attention control mechanisms and their underlying neural structures in the frontal-striatal system, such as the dorsal anterior cingulate cortex/pre-supplemental area and the left caudate.

Methods: We employed longitudinal neuroimaging and functional connectivity methods in a small group of multilingual children over two years.

Results: We found that the dACC/preSMA is functionally influenced by changes in multilingual competence but not yet structurally adapted, while the left caudate, in a developmental stage, is influenced, adapts, and specializes due to multilingual experience. Furthermore, increases in multilingual competence strengthen connections between the dACC/preSMA, left caudate, and other structures of the cognitive control network, such as the right inferior frontal gyrus and bilateral inferior parietal lobules.

Conclusions: These findings suggest that multilingual competence impacts brain "adaptation" and "specialization" during childhood. The results may provide insights and guide future research on experience-expectant and experience-dependent brain plasticity to explain the "interaction" between multilingualism and neurodevelopment.